stdlib/FreeBSD/exit.3

   1 .\" Copyright (c) 1990, 1991, 1993
   2 .\"     The Regents of the University of California.  All rights reserved.
   3 .\"
   4 .\" This code is derived from software contributed to Berkeley by
   5 .\" the American National Standards Committee X3, on Information
   6 .\" Processing Systems.
   7 .\"
   8 .\" Redistribution and use in source and binary forms, with or without
   9 .\" modification, are permitted provided that the following conditions
  10 .\" are met:
  11 .\" 1. Redistributions of source code must retain the above copyright
  12 .\"    notice, this list of conditions and the following disclaimer.
  13 .\" 2. Redistributions in binary form must reproduce the above copyright
  14 .\"    notice, this list of conditions and the following disclaimer in the
  15 .\"    documentation and/or other materials provided with the distribution.
  16 .\" 3. All advertising materials mentioning features or use of this software
  17 .\"    must display the following acknowledgement:
  18 .\"     This product includes software developed by the University of
  19 .\"     California, Berkeley and its contributors.
  20 .\" 4. Neither the name of the University nor the names of its contributors
  21 .\"    may be used to endorse or promote products derived from this software
  22 .\"    without specific prior written permission.
  23 .\"
  24 .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  25 .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  26 .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27 .\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  28 .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  29 .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  30 .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  31 .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  32 .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  33 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  34 .\" SUCH DAMAGE.
  35 .\"
  36 .\"     @(#)exit.3      8.1 (Berkeley) 6/4/93
  37 .\" $FreeBSD: src/lib/libc/stdlib/exit.3,v 1.13 2002/12/13 16:53:50 ru Exp $
  38 .\"
  39 .Dd September 9, 2002
  40 .Dt EXIT 3
  41 .Os
  42 .Sh NAME
  43 .Nm exit , _Exit
  44 .Nd perform normal program termination
  45 .Sh LIBRARY
  46 .Lb libc
  47 .Sh SYNOPSIS
  48 .In stdlib.h
  49 .Ft void
  50 .Fn exit "int status"
  51 .Ft void
  52 .Fn _Exit "int status"
  53 .Sh DESCRIPTION
  54 The
  55 .Fn exit
  56 and
  57 .Fn _Exit
  58 functions terminate a process.
  59 .Pp
  60 Before termination,
  61 .Fn exit
  62 performs the following functions in the order listed:
  63 .Bl -enum -offset indent
  64 .It
  65 Call the functions registered with the
  66 .Xr atexit 3
  67 function, in the reverse order of their registration.
  68 .It
  69 Flush all open output streams.
  70 .It
  71 Close all open streams.
  72 .It
  73 Unlink all files created with the
  74 .Xr tmpfile 3
  75 function.
  76 .El
  77 .Pp
  78 The
  79 .Fn _Exit
  80 function terminates without calling the functions registered with the
  81 .Xr atexit 3
  82 function, and may or may not perform the other actions listed.
  83 Both functions make the low-order eight bits of the
  84 .Fa status
  85 argument available to a parent process which has called a
  86 .Xr wait 2 Ns -family
  87 function.
  88 .Pp
  89 The C Standard
  90 .Pq St -isoC-99
  91 defines the values
  92 .Li 0 ,
  93 .Dv EXIT_SUCCESS ,
  94 and
  95 .Dv EXIT_FAILURE
  96 as possible values of
  97 .Fa status .
  98 Cooperating processes may use other values;
  99 in a program which might be called by a mail transfer agent, the
 100 the values described in
 101 .Xr sysexits 3
 102 may be used to provide more information to the parent process.
 103 .Pp
 104 Note that
 105 .Fn exit
 106 does nothing to prevent bottomless recursion should a function registered
 107 using
 108 .Xr atexit 3
 109 itself call
 110 .Fn exit .
 111 Such functions must call
 112 .Fn _Exit
 113 instead (although this has other effects as well which may not be desired).
 114 .Sh RETURN VALUES
 115 The
 116 .Fn exit
 117 and
 118 .Fn _Exit
 119 functions
 120 never return.
 121 .Sh SEE ALSO
 122 .Xr wait 2 ,
 123 .Xr _exit 2 ,
 124 .Xr atexit 3 ,
 125 .Xr intro 3 ,
 126 .Xr sysexits 3 ,
 127 .Xr tmpfile 3
 128 .Sh STANDARDS
 129 The
 130 .Fn exit
 131 and
 132 .Fn _Exit
 133 functions conform to
 134 .St -isoC-99 .